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Abstract:

An ultrasound diagnostic device has a control unit (18) which
sequentially selects transducers (2a) for supplying drive signals while
shifting a predetermined number of the transducers in a disposing
direction for each output of transmitted ultrasound waves. Then, an image
generation unit (14) generates image data for within a subject body for
each frame on the basis of received signals which have been sequentially
received by a receiving unit (13). Next, the control unit (18) performs
switching between selection of m units of transducers (2a) to be
consecutively positioned, and selection of m+1 units of the transducers
(2a) to be consecutively positioned, for each frame. In addition, the
control unit (18) generates synthesized image data acquired by
synthesizing image data of at least two consecutive frames each time that
image data is generated for each frame.

Claims:

1. An ultrasound diagnostic device comprising: an ultrasound probe which
includes n pieces of transducers being arranged in parallel, n satisfying
n>1, the transducers outputting transmitted ultrasound waves toward a
test body by a drive signal, and outputting received signals by receiving
reflected ultrasound waves from the test body; a transmitter unit which
supplies the drive signal to selected transducers from among the n pieces
of transducers; a receiver unit which receives received signals to be
outputted from the selected transducers; a control unit which
sequentially selects the transducers, the transducers being supplied with
the drive signal, while shifting the transducers by a predetermined
number in an array direction every time when each of the transmitted
ultrasound waves is outputted; and an image processing unit which creates
image data of an inside of the test body for each frame based on the
received signals sequentially received by the receiver unit, wherein,
while making a switch for each frame, the control unit executes selection
of m pieces of the transducers arranged consecutively and selection of
m+1 pieces of the transducers arranged consecutively, m satisfying
m<n, and every time when the image data of each frame is created, the
control unit creates synthetic image data obtained by synthesizing image
data of at least two consecutive frames with each other.

2. The ultrasound diagnostic device according to claim 1, further
comprising: a storage unit which at least stores image data of a range
from a latest frame among the two consecutive frames to a third latest
frame, wherein the control unit creates pixel data of a pixel in the
synthetic image data, the pixel data corresponding to a changed portion
of a pixel between image data of the latest frame and image data of the
third latest frame, based on pixel data in image data of a second latest
frame, the pixel data corresponding to a pixel adjacent to the pixel.

3. The ultrasound diagnostic device according to claim 2, wherein the
control unit sets the pixel data of the pixel in the synthetic image
data, the pixel data corresponding to the changed portion of the pixel,
to one obtained by interpolation from the pixel data in the image data of
the second latest frame, the pixel data individually corresponding to
pixels adjacent to both sides of the pixel in an azimuth direction.

4. The ultrasound diagnostic device according to claim 2, wherein the
control unit sets the pixel data of the pixel in the synthetic image
data, the pixel data corresponding to the changed portion of the pixel,
to the same one as the pixel data in the image data of the second latest
frame, the pixel data corresponding to a pixel adjacent to either side of
the pixel in an azimuth direction.

5. The ultrasound diagnostic device according to claim 2, wherein the
control unit sets pixel data of a pixel in the synthetic image data, the
pixel data corresponding to a portion where there is no change of a pixel
between the image data of the latest frame and the image data of the
third frame, to pixel data of a pixel in the image data of the latest
frame, the pixel data corresponding to the pixel.

6. The ultrasound diagnostic device according to claim 2, wherein the
control unit determines whether or not two pixels adjacent to each other
in the azimuth direction in the image data of the second latest frame,
the two pixels serving as determination subject pixels, satisfy a
predetermined correlation condition, and when the correlation condition
is satisfied as a result of the determination, sets pixel data of a pixel
to be arranged between two pixels in the synthetic image, the pixels
corresponding to the determination subject pixels, to one created based
on pixel data related to the determination subject pixels.

7. The ultrasound diagnostic device according to claim 6, wherein the
control unit determines, as the correlation condition, whether or not a
brightness difference between the determination subject pixels is a
predetermined threshold value or less.

8. A nontransitory computer-readable medium having stored thereon a
program that is executable by a computer, the computer being provided in
an ultrasound diagnostic device including an ultrasound probe which
includes n pieces of transducers being arranged in parallel, n satisfying
n>1, the transducers outputting transmitted ultrasound waves toward a
test body by a drive signal, and outputting received signals by receiving
reflected ultrasound waves from the test body, the program being
executable by the computer to execute functions comprising: a
transmission function to supply the drive signal to selected transducers
among the n pieces thereof; a reception function to receive received
signals to be outputted from the selected transducers; a control function
to sequentially select the transducers, the transducers being to be
supplied with the drive signal, while shifting the transducers by a
predetermined number in an array direction every time when each of the
transmitted ultrasound waves is outputted, and, while making switch for
each frame, to execute selection of m pieces of the transducers arranged
consecutively and selection of m+1 pieces of the transducers arranged
consecutively, m satisfying m<n; and an image processing function to
create image data of an inside of the test body for each frame based on
the received signals sequentially received by the receiver unit, and,
every time when the image data of each frame is created, to at least
create synthetic image data obtained by synthesizing image data of two
consecutive frames with each other.

9. The ultrasound diagnostic device according to claim 3, wherein the
control unit sets pixel data of a pixel in the synthetic image data, the
pixel data corresponding to a portion where there is no change of a pixel
between the image data of the latest frame and the image data of the
third frame, to pixel data of a pixel in the image data of the latest
frame, the pixel data corresponding to the pixel.

10. The ultrasound diagnostic device according to claim 4, wherein the
control unit sets pixel data of a pixel in the synthetic image data, the
pixel data corresponding to a portion where there is no change of a pixel
between the image data of the latest frame and the image data of the
third frame, to pixel data of a pixel in the image data of the latest
frame, the pixel data corresponding to the pixel.

11. The ultrasound diagnostic device according to claim 3, wherein the
control unit determines whether or not two pixels adjacent to each other
in the azimuth direction in the image data of the second latest frame,
the two pixels serving as determination subject pixels, satisfy a
predetermined correlation condition, and when the correlation condition
is satisfied as a result of the determination, sets pixel data of a pixel
to be arranged between two pixels in the synthetic image, the pixels
corresponding to the determination subject pixels, to one created based
on pixel data related to the determination subject pixels.

12. The ultrasound diagnostic device according to claim 4, wherein the
control unit determines whether or not two pixels adjacent to each other
in the azimuth direction in the image data of the second latest frame,
the two pixels serving as determination subject pixels, satisfy a
predetermined correlation condition, and when the correlation condition
is satisfied as a result of the determination, sets pixel data of a pixel
to be arranged between two pixels in the synthetic image, the pixels
corresponding to the determination subject pixels, to one created based
on pixel data related to the determination subject pixels.

Description:

TECHNICAL FIELD

[0001] The present invention relates to an ultrasound diagnostic device
and a program.

BACKGROUND ART

[0002] Heretofore, there has been known an ultrasound diagnostic device,
which has an oscillating probe (probe) including a large number of
transducers by arraying the same one-dimensionally or two-dimensionally,
selects a plurality of the transducers consecutively arranged among the
large number of transducers, performs transmission/reception for an
ultrasound wave, which is generated by beam forming, for a test subject
such as a living body by the selected transducers, performs scanning
(linear scanning) for a predetermined range thereof by repeating the
transmission/reception of the ultrasound wave while shifting the
transducers to be selected, and creates an ultrasound image, which is in
accordance with the B mode and for each frame, based on data obtained as
a result of this scanning.

[0003] Here, as shown in FIG. 26, a minimum value of an interval q between
targets (focus points) T to be specified by ultrasound beams created by
the beam forming is equal to an arrangement interval p between
transducers 1002a. That is to say, the minimum value (azimuth resolution)
of the recognizable interval q between the targets T depends on the
arrangement interval p between the transducers 1002a. Therefore, in the
ultrasound diagnostic device as mentioned above, the arrangement interval
between the transducers just needs to be reduced in order to enhance the
azimuth resolution; however, there are physical limitations thereon.

[0004] Accordingly, in the conventional ultrasound diagnostic device,
there is one configured as follows. After the transmission/reception for
the ultrasound wave is performed a predetermined number of times while
shifting the transducers to be selected, a transducer array itself is
moved by a predetermined distance in an array direction, the
transmission/reception for the ultrasound wave is performed a
predetermined number of times in a similar way, and such a
transmission/reception operation is executed a plurality of times in one
frame, then received signals obtained as a result are synthesized with
one another, and image data for one frame is created (for example, Patent
Literature 1).

[0005] Moreover, as shown in FIG. 27, it is also known to change the
number of transducers 1002a, which are to be selected for each
transmission/reception of the ultrasound wave, alternately to odd
numbers/even numbers, and the scanning is performed while shifting the
targets T (for example, Non-Patent Literature 1).

[0008] However, though in the ultrasound diagnostic device described in
the foregoing patent literature, the azimuth resolution can be enhanced
since the interval between the targets can be reduced while the
arrangement interval between the transducers is being left as it is, a
frame rate is lowered since the number of transmission/reception times of
the ultrasound wave in one frame is increased, and an accurate diagnosis
is inhibited from being performed. Moreover, complicated mechanism and
device for moving the transducer array are required, and cost is
increased.

[0009] Moreover, also in the technology shown in FIG. 27, though the
azimuth resolution can be enhanced since the interval q between the
targets T becomes a half of the arrangement interval p between the
transducers 1002a, the frame rate is still lowered since the number of
transmission/reception times of the ultrasound wave in one frame is
increased.

[0010] It is an object of the present invention to provide an ultrasound
diagnostic device and a program, which are capable of enhancing the
azimuth resolution while suppressing the frame rate from being lowered.

Means for Solving the Problems

[0011] In order to achieve the foregoing object, an invention according to
claim 1 is an ultrasound diagnostic device comprising:

[0012] an ultrasound probe which includes n (n>1) pieces of transducers
being arranged in parallel, the transducers outputting transmitted
ultrasound waves toward a test body by a drive signal, and outputting
received signals by receiving reflected ultrasound waves from the test
body;

[0013] a transmitter unit which supplies the drive signal to selected
transducers among the n pieces thereof;

[0014] a receiver unit which receives received signals to be outputted
from the selected transducers;

[0015] a control unit which sequentially selects the transducers, the
transducers being to be supplied with the drive signal, while shifting
the transducers by a predetermined number in an array direction every
time when each of the transmitted ultrasound waves is outputted; and

[0016] an image processing unit which creates image data of an inside of
the test body for each frame based on the received signals sequentially
received by the receiver unit,

[0017] wherein, while making switch for each frame, the control unit
executes selection of m (m<n) pieces of the transducers arranged
consecutively and selection of m+1 pieces of the transducers arranged
consecutively, and every time when the image data of each frame is
created, at least creates synthetic image data obtained by synthesizing
image data of two consecutive frames with each other.

[0018] The invention according to claim 2 is the ultrasound diagnostic
device according to claim 1, further comprising:

[0019] a storage unit which at least stores image data of a range from a
latest frame among the two consecutive frames to a third latest frame,

[0020] wherein the control unit creates pixel data of a pixel in the
synthetic image data, the pixel data corresponding to a changed portion
of a pixel between image data of the latest frame and image data of the
third latest frame, based on pixel data in image data of a second latest
frame, the pixel data corresponding to a pixel adjacent to the pixel.

[0021] The invention according to claim 3 is the ultrasound diagnostic
device according to claim 2, wherein the control unit sets the pixel data
of the pixel in the synthetic image data, the pixel data corresponding to
the changed portion of the pixel, to one obtained by interpolation from
the pixel data in the image data of the second latest frame, the pixel
data individually corresponding to pixels adjacent to both sides of the
pixel in an azimuth direction.

[0022] The invention according to claim 4 is the ultrasound diagnostic
device according to claim 2, wherein the control unit sets the pixel data
of the pixel in the synthetic image data, the pixel data corresponding to
the changed portion of the pixel, to the same one as the pixel data in
the image data of the second latest frame, the pixel data corresponding
to a pixel adjacent to either side of the pixel in an azimuth direction.

[0023] The invention according to claim 5 is the ultrasound diagnostic
device according to any one of claims 2 to 4, wherein the control unit
sets pixel data of a pixel in the synthetic image data, the pixel data
corresponding to a portion where there is no change of a pixel between
the image data of the latest frame and the image data of the third frame,
to pixel data of a pixel in the image data of the latest frame, the pixel
data corresponding to the pixel.

[0024] The invention according to claim 6 is the ultrasound diagnostic
device according to any one of claims 2 to 4, wherein the control unit
determines whether or not two pixels adjacent to each other in the
azimuth direction in the image data of the second latest frame, the two
pixels serving as determination subject pixels, satisfy a predetermined
correlation condition, and when the correlation condition is satisfied as
a result of the determination, sets pixel data of a pixel to be arranged
between two pixels in the synthetic image, the pixels corresponding to
the determination subject pixels, to one created based on pixel data
related to the determination subject pixels.

[0025] The invention according to claim 7 is the ultrasound diagnostic
device according to claim 6, wherein the control unit determines, as the
correlation condition, whether or not a brightness difference between the
determination subject pixels is a predetermined threshold value or less.

[0026] The invention according to claim 8 is a program for allowing a
computer, the computer being provided in an ultrasound diagnostic device
including an ultrasound probe which includes n (n>1) pieces of
transducers being arranged in parallel, the transducers outputting
transmitted ultrasound waves toward a test body by a drive signal, and
outputting received signals by receiving reflected ultrasound waves from
the test body, to realize: a transmission function to supply the drive
signal to selected transducers among the n pieces thereof;

[0027] a reception function to receive received signals to be outputted
from the selected transducers;

[0028] a control function to sequentially select the transducers, the
transducers being to be supplied with the drive signal, while shifting
the transducers by a predetermined number in an array direction every
time when each of the transmitted ultrasound waves is outputted, and,
while making switch for each frame, to execute selection of m (m<n)
pieces of the transducers arranged consecutively and selection of m+1
pieces of the transducers arranged consecutively; and

[0029] an image processing function to create image data of an inside of
the test body for each frame based on the received signals sequentially
received by the receiver unit, and, every time when the image data of
each frame is created, to at least create synthetic image data obtained
by synthesizing image data of two consecutive frames with each other.

Effects of the Invention

[0030] In accordance with the present invention, the azimuth resolution
can be enhanced while suppressing the frame rate from being lowered.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 is a view showing an exterior appearance configuration of an
ultrasound diagnostic device in an embodiment of the present invention.

[0032]FIG. 2 is a block diagram showing a schematic configuration of the
ultrasound diagnostic device.

[0033] FIG. 3 is a view explaining an arrangement configuration of
transducers provided in an ultrasound probe.

[0034] FIG. 4 is a functional block diagram for explaining a creation
procedure of image data according to the embodiment of the present
invention.

[0058] A description is made below of ultrasound diagnostic devices
according to embodiments of the present invention with reference to the
drawings. However, the scope of the invention is not limited to
illustrated examples. Note that, in the following description, the same
reference numerals are assigned to those having the same functions and
configurations, and a description thereof is omitted.

First Embodiment

[0059] As shown in FIG. 1 and FIG. 2, an ultrasound diagnostic device S
according to a first embodiment of the present invention is composed by
including: an ultrasound probe 2, which transmits an ultrasound wave
(transmitted ultrasound wave) to a test subject (not shown) such as a
living body, and in addition, receives an ultrasound reflected wave
(reflected ultrasound wave: echo) reflected on this test subject; and an
ultrasound diagnostic device body 1, which is connected to the ultrasound
probe 2 through a cable 3, allows the ultrasound probe 2 to transmit the
transmitted ultrasound wave to the test subject by transmitting a drive
signal as an electric signal to the ultrasound probe 2, and in addition,
images an internal state of the test subject as an ultrasound image based
on a received signal as an electric signal created by the ultrasound
probe 2 in response to the reflected ultrasound wave from an inside of
the test subject, which is received in the ultrasound probe 2.

[0060] The ultrasound probe 2 includes transducers 2a composed of
piezoelectric elements, and as shown in FIG. 3, a plurality of the
transducers 2a are arrayed in a one-dimensional array form in an azimuth
direction (scanning direction or vertical direction). In this embodiment,
the ultrasound probe 2, which includes n pieces (for example, 128 pieces)
of the transducers 2a, is used. Note that the transducers 2a may be those
arrayed in a two-dimensional array form. Moreover, the number of
transducers 2a may be set arbitrarily as long as the number is plural.
Moreover, in this embodiment, with regard to the ultrasound probe 2, one
that conducts a linear scanning mode is applied; however, those which
conduct a sector scanning mode and a convex scanning mode may be applied.

[0062] For example, the operation input unit 11 includes a variety of
switches, buttons, a track ball, a mouse, a keyboard and the like, which
are for performing input of a command to instruct a start of a diagnosis
and of data such as personal information of the test subject, and the
like, and outputs an operation signal to the control unit 18.

[0063] The transmitter unit 12 is a circuit, which, in accordance with
control of the control unit 18, supplies the drive signal as the electric
signal to the ultrasound probe 2 through the cable 3, and allows the
ultrasound probe 2 to generate the ultrasound wave. Moreover, for
example, the transmitter unit 12 includes a clock generation circuit, a
delay circuit, and a pulse generation circuit. The clock generation
circuit is a circuit, which generates a clock signal that decides
transmission timing and transmission frequency of the drive signal. The
delay circuit is a circuit for setting a delay time for each individual
route corresponding to each of the transducers 2a with regard to the
transmission timing of the drive signal, delaying the transmission of the
drive signal by the set delay time, and focusing transmitted beams
composed of such transmitted ultrasound waves thus delayed. The pulse
generation circuit is a circuit for generating a pulse signal as the
drive signal in a predetermined cycle.

[0064] The receiver unit 13 is a circuit, which receives the received
signal as the electric signal from the ultrasound probe 2 through the
cable 3 in accordance with control of the control unit 18. For example,
the receiver unit 13 includes an amplifier, an A/D converter circuit, and
a phasing/adding circuit. The amplifier is a circuit for amplifying the
received signal by a predetermined amplification factor, which is set in
advance, for each individual route corresponding to each of the
transducers 2a. The A/D converter circuit is a circuit for performing A/D
conversion for the received signal thus amplified. The phasing/adding
circuit is a circuit for giving a delay time to the received signal,
which is subjected to the A/D conversion, for each individual route
corresponding to each of the transducers 2a to phase a time phase
thereof, adding (phasing/adding) such received signals to one another to
create sound ray data.

[0065] The image creation unit 14 implements logarithmic amplification,
envelope detection processing and the like for the sound ray data coming
from the receiver unit 13, and creates B-mode image data. The B-mode
image data created in such a manner is transmitted to the memory unit 15.

[0066] For example, the memory unit 15 is composed of a semiconductor
memory such as a DRAM (Dynamic Random Access Memory), and stores the
B-mode image frame, which is transmitted from the image creation unit 14,
in a unit of frame. That is to say, the memory unit 15 can store the
B-mode image frame as frame image data. As will be described later, the
memory unit 15 includes frame buffers for an amount of two frames
correspondingly to each of frames for which odd-number scanning is
executed and of frames for which even-number scanning is executed, and
can store the frame image data in the frame buffers. The frame image data
stored in the memory unit 15 is made capable of being read out by the
control unit 18. Moreover, as will be described later, the memory unit 15
is used as a work area in the event of creating synthetic image data by
the control unit 18. Then, the created synthetic image data is
transmitted to the DSC 16 in accordance with control of the control unit
18.

[0067] The DSC 16 converts the synthetic image data, which is created by
the control unit 18, into an image signal in accordance with a scanning
mode of a television signal, and outputs the image signal to the display
unit 17.

[0068] The display unit 17 is a display device such as an LCD (Liquid
Crystal Display), a CRT (Cathode-Ray Tube) display, an organic EL
(Electronic Luminescence) display, and a plasma display. The display unit
17 performs display of an image on a display screen in accordance with
the image signal outputted from the DSC 16. Note that a printing device
such as a printer may be applied in place of the display device.

[0069] For example, the control unit 18 is composed by including a CPU
(Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random
Access Memory), reads out a variety of processing programs such as a
system program stored in the ROM, expands the processing programs in the
RAM, and controls operations of the respective units of the ultrasound
diagnostic device S in accordance with the expanded programs.

[0070] The ROM is composed of a nonvolatile memory such as a
semiconductor, and the like, and stores the system program corresponding
to the ultrasound diagnostic device S, the various programs of processing
such as pulse transmission processing, pulse reception processing, and
image data synthesis processing, which are executable on the system
program concerned and will be described later, a variety of data, and the
like. These programs are stored in a form of a program code readable by a
computer, and the CPU sequentially executes operations which conform to
the program code concerned. The RAM forms a work area that temporarily
stores the variety of programs to be executed by the CPU and data related
to these programs.

[0071] Next, while referring to FIG. 4, a description is made of functions
in the respective units for creating the synthetic image data based on
the received signal coming from the ultrasound probe 2 by the ultrasound
diagnostic device S configured as described above.

[0072] As shown in FIG. 4, the receiver unit 13 includes a switch 13a, an
odd number scanning unit 13b, and an even number scanning unit 13c.

[0073] The switch 13a is one that switches a route of the received signal
by control of the control unit 18. When the receiver unit 13 receives the
received signal from the ultrasound probe 2, the switch 13a is switched
for either of an odd number frame or an even number frame, which will be
described later, depending on whether the received signal belongs to the
odd number frame or the even number frame, the received signal is sent to
the odd number scanning unit 13b or the even number scanning unit 13c,
the creation of the sound ray data is performed, and the created sound
ray data is outputted to the image creation unit 14. As will be described
later, the odd number frames and the even number frames are alternately
executed for each of the frames, and accordingly, the switch 13a switches
alternately for each of the frames. The image creation unit 14 includes
an odd-numbered scan B-mode image creation unit 14a and an even-numbered
scan B-mode image creation unit 14b, and in each thereof, processes the
sound ray data outputted from the receiver unit 13, and creates the
B-mode image data. That is to say, based on the sound ray data outputted
from the odd number scanning unit 13b, the odd-numbered scan B-mode image
creation unit 14a creates the B-mode image data, and based on the sound
ray data outputted from the even number scanning unit 13c, the even
numbered scan B-mode image creation unit 14b creates the B-mode image
data. Then, the B-mode image data created in the odd-numbered scan B-mode
image creation unit 14a and the even-numbered scan B-mode image creation
unit 14b are outputted to the memory unit 15.

[0075] The odd-numbered scan B-mode image data memory unit 15a can at
least store frame image data of an amount of two frames, and frame image
data created in a latest odd number frame and frame image data created in
a second latest odd number frame are stored therein. Note that, for the
purpose of enhancing accuracy of motion determination by the frame
difference motion detection unit 18c to be described later, frame image
data created in third latest odd number frame or more can be further
stored therein.

[0076] Moreover, the even-numbered scan B-mode image data memory unit 15b
can at least store frame image data of an amount of two frames, and frame
image data created in a latest even number frame and frame image data
created in a second latest even number frame are stored therein. Note
that, for the purpose of enhancing the accuracy of the motion
determination by the frame difference motion detection unit 18c to be
described later, frame image data created in third latest even number
frame or more can be further stored therein.

[0077] The control unit 18 includes an odd-numbered scan vertical data
correlation detection unit 18a, an even-numbered scan vertical data
correlation detection unit 18b, a frame difference motion detection unit
18c, an interpolated data method selection unit 18d, an interpolated data
selection unit 18e, and an image data synthesis unit 18f. Configurations
of these respective units are those to be realized by execution of
software programs by the control unit 18. Note that it is also possible
to realize the configurations of these respective units by hardware.

[0078] In the case where the latest frame is an even number frame, the
odd-numbered scan vertical data correlation detection unit 18a reads out
frame image data, which is created in an odd number frame immediately
before the latest even number frame, from the odd-numbered scan B-mode
image data memory unit 15a, extracts two pixels (determination subject
pixels) adjacent to each other in the scanning direction, and determines
a correlation therebetween. Specifically, the odd-numbered scan vertical
data correlation detection unit 18a performs determination as to whether
or not the correlation is strong based on whether or not a brightness
difference between the extracted two pixels is less than a predetermined
threshold value. For example, in the case where brightness is represented
by 256 steps, this threshold value is set at "20"; however, it is
possible to set the threshold value at any value as long as the threshold
value is within a range where it can be determined that the correlation
is strong. Then, the odd-numbered scan vertical data correlation
detection unit 18a sends a determination result of the correlation to the
interpolated data method selection unit 18d. This determination of the
correlation is performed for all pixels in the frame image data created
in the odd number frame immediately before the latest even number frame.

[0079] In the case where the latest frame is an odd number frame, the
even-numbered scan vertical data correlation detection unit 18b reads out
frame image data, which is created in an even number frame immediately
before the latest odd number frame, from the even-numbered scan B-mode
image data memory unit 15b, extracts two pixels (determination subject
pixels) adjacent to each other in the scanning direction, and determines
a correlation therebetween. A specific determination method is similar to
that of the odd-numbered scan vertical data correlation detection unit
18a, and accordingly, a description thereof is omitted. Then, the
even-numbered scan vertical data correlation detection unit 18b sends a
determination result of the correlation to the interpolated data method
selection unit 18d. This determination of the correlation is performed
for all pixels in the frame image data created in the even number frame
immediately before the latest odd number frame. The frame difference
motion detection unit 18c reads out the frame image data of the latest
frame and the frame image data of the third latest frame, extracts pixels
on the same coordinate, compares brightnesses thereof with each other,
and performs the motion determination. Specifically, for example, in the
case where the latest frame is an odd number frame, the frame image data
created in the latest odd number frame and the frame image data created
in the second latest odd number frame (that is, the third latest frame)
are read out from the odd-numbered scan B-mode image data memory unit
15a, and pixels on the same coordinate are extracted. Then, it is
determined whether or not a brightness difference between these pixels is
less than a predetermined threshold value, whereby determination as to
whether or not the pixel concerned has moved. For example, this threshold
value is set at "15"; however, it is possible to set the threshold value
at any value as long as the threshold value is within a range where it
can be determined that the pixel has moved. Then, the frame difference
motion detection unit 18c sends a result of the motion determination to
the interpolated data method selection unit 18d. This motion
determination is performed for all pixels in the read out frame image
data.

[0080] In this embodiment, the motion determination is performed in such a
manner as described above; however, for the purpose of enhancing the
accuracy of the motion determination, there may be adopted such a
configuration that both of the brightness difference of the pixels
between the latest frame and the third latest frame and of a brightness
difference of pixels between the third latest frame and the fifth latest
frame are determined, and that the motion determination is performed
based on results of this determination. Moreover, there may be adopted
such a configuration that a brightness difference of pixels between
frames before the fifth latest frame is further determined, and that a
result of this determination is used for the motion determination.

[0081] The interpolated data method selection unit 18d receives the
individual determination results from the odd-numbered scan vertical data
correlation detection unit 18a, the even-numbered scan vertical data
correlation detection unit 18b and the frame difference motion detection
unit 18c, selects a creation method of the respective pixels in the event
of creating the synthetic image data to be described later, and sends
information of such selection to the interpolated data selection unit. In
the first embodiment, the selectable creation method of the pixels is a
method of extracting a pixel, which corresponds to a pixel that becomes
adjacent to a pixel (pixel of interest) serving as a subject in the event
where the synthetic image data is created, from the frame image data of
the second latest frame, and of obtaining interpolated pixel data, or the
like.

[0082] The interpolated data selection unit 18e receives such selection
information coming from the interpolated data method selection unit 18d,
reads out necessary frame image data from the odd-numbered scan B-mode
image data memory unit 15a and the even-numbered scan B-mode image data
memory unit 15b, extracts pixel data of a pixel, which is necessary to
create the pixel of interest, from the read out frame image data, and
creates the pixel data of the pixel of interest. The interpolated data
selection unit 18e sends the created image data to the image data
synthesis unit 18f.

[0083] The image data synthesis unit 18f reads out the frame image data of
the latest frame and the frame image data of the second latest frame from
the odd-numbered scan B-mode image data memory unit 15a and the
even-numbered scan B-mode image data memory unit 15b, synthesizes the
respective readout frame image data with each other, and creates the
synthetic image data. Moreover, when the pixel data sent from the
interpolated data selection unit 18e is present, the image data synthesis
unit 18f writes the pixel data concerned to the synthetic image data.
Then, the synthetic image data created in such a manner is outputted to
the display unit 17 through the DSC 16.

[0084] Next, while referring to FIG. 5, a description is made of the pulse
transmission processing to be executed in the ultrasound diagnostic
device S configured in such a manner as described above. This pulse
transmission processing is processing to be executed when scanning in one
frame is started. Note that FIG. 5 is a flowchart showing a case where,
in a case where a constant m is an odd number, a frame (odd number
frame), in which m pieces of the transducers 2a arranged consecutively in
the scanning direction are driven to perform the scanning, and a frame
(even number frame), in which m+1 pieces of the transducer 2a are driven
to perform the scanning, are alternately performed. However, a
configuration may be adopted, in which, the constant m is defined to be
an even number, and a frame (even number frame), in which m pieces of the
transducers 2a are driven to perform the scanning, and a frame (odd
number frame), in which m+1 pieces of the transducer 2a are driven to
perform the scanning, are alternately performed.

[0085] First, the control unit 18 sets 1 to a variable a indicating the
number of output times of the transmitted ultrasound wave (Step S101),
and determines whether or not a frame at this time is an odd number frame
(Step S102). Here, the odd number frame is a frame, in which
predetermined odd-number pieces (m pieces in the example shown in FIG. 5)
of the transducers 2a are driven to perform the scanning, and the even
number frame is a frame, in which the transducers 2a of which number (m+1
pieces in the example shown in FIG. 5) is larger (or smaller) by one than
that of the transducers 2a to be driven in the odd number frame are
driven to perform the scanning.

[0086] In the case where it is determined that the frame at this time is
an odd number frame (Step S102: Y), the control unit 18 turns on a route
from the transducer 2a arranged at an [a]-th position corresponding to a
variable a to the transducer 2a arranged at an [a+m-1]-th position, and
conducts the route concerned to the pulse generation circuit of the
transmitter unit 12 (Step S103). That is to say, the control unit 18
makes conduction between the pulse generation circuit and m pieces (m is
an odd number) of the transducers 2a arranged consecutively in the
scanning direction, the transducers 2a including the transducer 2a
located at the position corresponding to the variable a. A specific
description is made with reference to FIG. 3. For example, when the
number of output times is third, and the number of transducers 2a to be
driven for each single output of the transmitted ultrasound wave is
defined to be (m=3) pieces, the third to fifth transducers 2a and the
pulse generation circuit are conducted to each other. Then, the
respective transducers 2a output such transmitted ultrasound waves at
predetermined pieces of timing thereof in response to the output of the
pulse signal by the pulse generation circuit, whereby the transmitted
beams are formed. Note that the constant m can be set arbitrarily as long
as the constant m is smaller than the number (n pieces) of the
transducers 2a provided in the ultrasound probe 2.

[0087] Next, the control unit 18 determines whether or not the variable a
is equal to [n-m+1] (Step S104). That is to say, the control unit 18
determines whether or not the transmitted beam is the last transmitted
beam in one frame, which is outputted in such a manner that m pieces of
the transducers 2a including the transducer 2a arrayed in the n-th order
are driven. When the control unit 18 determines that the transmitted beam
concerned is a transmitted beam outputted last time in one frame (Step
S104: Y), the control unit 18 ends this processing, and meanwhile, when
the control unit 18 does not determine that the transmitted beam
concerned is the transmitted beam outputted last time in one frame (Step
S104: N), the control unit 18 shifts to processing of Step S107.

[0088] Moreover, when the control unit 18 does not determine that the
frame at this time is an odd number frame in Step S102, that is, when the
frame at this time is an even number frame (Step S102: N), the control
unit 18 turns on a rout from the transducer 2a arranged at the [a]-th
position corresponding to the variable a to the transducer 2a arranged at
an [a+m]-th position, and conducts the route concerned to the pulse
generation circuit of the transmitter unit 12 (Step S105). That is to
say, the control unit 18 makes conduction between the pulse generation
circuit and [m+1] pieces of the transducers 2a arranged consecutively in
the scanning direction, the transducers 2a including the transducer 2a
located at the position corresponding to the variable a. Then, the
respective transducers 2a output the transmitted ultrasound waves at
predetermined pieces of timing thereof in response to the output of the
pulse signal by the pulse generation circuit, whereby the transmitted
beams are formed.

[0089] Next, the control unit 18 determines whether or not the variable a
is equal to [n-m] (Step S106). That is to say, the control unit 18
determines whether or not the transmitted beam concerned is the last
transmitted beam in one frame, which is outputted in such a manner that
[m+1] pieces of the transducers 2a including the transducer 2a arrayed in
the n-th order are driven. When the control unit 18 determines that the
transmitted beam concerned is a transmitted beam outputted last time in
one frame (Step S106: Y), the control unit 18 ends this processing, and
meanwhile, when the control unit 18 does not determine that the
transmitted beam concerned is the transmitted beam outputted last time in
one frame (Step S106: N), the control unit 18 shifts to processing of
Step S107.

[0090] In Step S107, the control unit 18 waits for elapse of a
predetermined time (t) (Step S107), and shifts to processing of Step
S108. This time (t) is set at a cycle in which the pulse signal is
generated by the pulse generation circuit of the transmitter unit 12.
Then, the control unit 18 adds one to the variable a (Step S108), and
shifts to the processing of Step S102.

[0091] Next, while referring to FIG. 6, a description is made of the pulse
reception processing. This pulse reception processing is processing to be
executed when the scanning in one frame is started.

[0092] First, the control unit 18 determines whether or not the frame at
this time is an odd number frame (Step S201). When the control unit 18
determines that the frame at this time is an odd number frame (Step S201:
Y), the control unit 18 switches the switch 13a of the receiver unit 13
so that the received signal coming from the ultrasound probe 2 can be
inputted to the odd number scanning unit 13b (Step S202). Meanwhile, when
the control unit 18 does not determine that the frame at this time is an
odd number frame, that is, determines that the frame at this time is an
even number frame (Step S201: N), the control unit 18 switches the switch
13a of the receiver unit 13 so that the received signal coming from the
ultrasound probe 2 can be inputted to the even number scanning unit 13c
(Step S203). Then, the control unit 18 waits until scanning for one frame
is completed (Step S204), and ends this processing. That is to say, when
the input of the received signal that is based on the last output of the
transmitted beam in one frame is completed, this processing is ended.

[0093] Next, while referring to FIG. 7, a description is made of the image
data synthesis processing according to the first embodiment of the
present invention. This image data synthesis processing is processing to
be executed when the frame image data of the latest frame is stored in
the memory unit 15. Here, the latest frame refers to a latest frame
between two consecutive frames which serve as bases for creating the
synthetic image data, and in usual, there applies a latest frame in the
frames in which the frame image data is stored in the memory unit 15 at
the point of time of performing the image data synthesis processing;
however, the latest frame is not necessarily limited to this. For
example, in the event of creating the synthetic image data, frame image
data obtained after the frames which serve as the bases for creating the
synthetic image data are obtained may be already stored in the memory
unit 15. Note that, in the first embodiment, the odd-numbered scan
vertical data correlation detection unit 18a and the even-numbered scan
vertical data correlation detection unit 18b do not function, and only by
the frame difference motion detection unit 18c, the selection of the
creation method of the pixels by the interpolated data method selection
unit 18d is performed.

[0094] First, the control unit 18 refers to the work area in the memory
unit 15, which is for creating the synthetic image data, and determines
whether or not the subject of the pixel data of the pixel of interest,
which is the pixel of the determination subject, is pixel data in the
frame image data of the latest frame (Step S301).

[0095] When the control unit 18 does not determine that the subject of the
pixel data of the pixel of interest is the pixel data in the frame image
data of the latest frame (Step S301: N), the control unit 18 uses, as the
pixel data of the pixel of interest, the pixel data in the frame image
data of the second latest frame (even number frame immediately before the
latest frame, for example, in the case where the latest frame is an odd
number frame) (Step S302). That is to say, by a function of the image
data synthesis unit 18f, the control unit 18 reads out the frame image
data of the second latest frame from the memory unit 15, extracts pixel
data of a pixel that coincides with the pixel of interest on the
coordinate, and writes the extracted pixel data into the work area of the
memory 15.

[0096] Meanwhile, when the control unit 18 determines that the subject of
the pixel data of the pixel of interest is the pixel data in the frame
image data of the latest frame (Step S301: Y), then by a function of the
frame difference motion detection unit 18c, the control unit 18 detects a
brightness difference between the pixel data in the frame image data of
the latest frame and the pixel data in the frame image data of the third
latest frame (odd number frame immediately before the latest frame, for
example, in the case where the latest frame is an odd number frame), and
performs the motion determination (Step S303).

[0097] Then, the control unit 18 determines whether or not the pixel of
interest does not move, that is, is in a static state as a result of the
motion determination (Step S304). When the control unit 18 determines
that the pixel of interest is in the static state (Step S304: Y), the
control unit 18 uses the pixel data in the frame image data of the latest
frame (Step S305). That is to say, by the function of the image data
synthesis unit 18f, the control unit 18 reads out the frame image data of
the latest frame from the memory unit 15, extracts the pixel data of the
pixel that coincides with the pixel of interest on the coordinate, and
writes the extracted pixel data into the work area of the memory 15. Note
that, in Step S305, in place of using the image data of the latest frame,
the image data of the third latest frame may be used, or an average value
of the image data of the latest frame and the image data of the third
latest frame, or the like may be used.

[0098] Meanwhile, when the control unit 18 does not determine in Step S304
that the pixel of interest is in the static state, that is, when the
pixel moves (Step S304: N), then by functions of the interpolated data
method selection unit 18d and the interpolated data selection unit 18e,
the control unit 18 extracts pixel data of pixels, which correspond to
pixels adjacent to the pixel of interest in the vertical direction
(scanning direction), from the frame image data of the second latest
frame, and writes interpolated data, which is created by obtaining an
average of the respective pixel data, into the work area of the memory
unit 15 (Step S306).

[0099] Then, the control unit 18 determines whether or not the synthesis
is completed for all the pixels (Step S307), and ends this processing
when the control unit 18 concerned determines that the synthesis is
completed (Step S307: Y). Meanwhile, when the control unit 18 does not
determine that the synthesis is not completed (Step S307: N), the control
unit 18 shifts the pixel of interest to an unprocessed pixel (Step S308),
and thereafter, shifts to the processing of Step S301.

[0100] Next, a description is made of an aspect of the scanning and a
creation process of the synthetic image data in the ultrasound diagnostic
device S configured in such a manner as mentioned above.

[0101] In each of the embodiments of the present invention, as shown in
FIG. 8A, when the first frame as an odd number frame is started, first to
third three transducers 2a are first driven, and transmitted ultrasound
waves are outputted to "a-ODD" taken as a target. Subsequently, second to
fourth transducers 2a are driven, and transmitted ultrasound waves are
outputted to "b-ODD" taken as a target. Below in a similar way, the
scanning is performed while shifting the transducers 2a, which are to be
driven, until output of transmitted ultrasound waves by drive of the
(n-2)-th to n-th transducers 2a is performed. Frame image data composed
of the respective sound ray data, which are "a-ODD (1)" to "N-ODD (1)" to
be created by this scanning, become as shown in FIG. 8E.

[0102] Then, as shown in FIG. 8B, when a second frame as an even number
frame is started, first to fourth four transducers 2a are first driven,
and transmitted ultrasound waves are outputted to "a-EVEN" taken as a
target. Note that a position of this target is located at an intermediate
between "a-ODD" and "b-ODD". Subsequently, second to fifth transducers 2a
are driven, and transmitted ultrasound waves are outputted to "b-EVEN"
taken as a target. Below in a similar way, the scanning is performed
while shifting the transducers 2a, which are to be driven until output of
transmitted ultrasound waves by drive of the (n-3) to n-th transducers 2a
is performed. Frame image data composed of the respective sound ray data,
which are "a-EVEN (2)" to "(N-1)-EVEN (2)" to be created by this
scanning, become as shown in FIG. 8F.

[0103] Subsequently, in a third frame as an odd number frame, as shown in
FIG. 8C, the scanning is performed in a similar way to the first frame,
and frame image data as shown in FIG. 8G is created.

[0104] Then, in a fourth frame as an even number frame, as shown in FIG.
8D, the scanning is performed in a similar way to the second frame, and
frame image data as shown in FIG. 8H is created. Below, also in a fifth
frame and after, frame image data are sequentially created in a similar
procedure.

[0105] The frame image data created in such a manner as described above
are synthesized with one another in an aspect as shown in FIG. 9, and the
synthetic image data is created. That is to say, first, when the frame
image data of the second frame is created, the respective sound ray data
in the frame image data of the first frame shown in FIG. 9A and the
respective sound ray data in the frame image data of the second frame
shown ion FIG. 9B are alternately superimposed on each other, and
synthetic image data as shown in FIG. 9E is created. Then, when the frame
image data of the third frame is created, the respective sound ray data
in the frame image data of the second frame shown in FIG. 9B and the
respective sound ray data in the frame image data of the third frame
shown in FIG. 9C are alternately superimposed on each other, and
synthetic image data as shown in FIG. 9F is created. Then, when the frame
image data of the fourth frame is created, the respective sound ray data
in the frame image data of the third frame shown in FIG. 9C and the
respective sound ray data in the frame image data of the fourth frame
shown ion FIG. 9D are alternately superimposed on each other, and
synthetic image data as shown in FIG. 9G is created.

[0106] A pitch of the targets of the synthetic image data created in such
a manner as described above becomes a half of a pitch of the targets in
the respective frame image data, and the azimuth resolution is enhanced.
Moreover, the synthetic image data is created every time when the frame
image data of each of the frames is created, and accordingly, the
lowering of the frame rate is suppressed.

[0107] Next, a description is specifically made of the synthetic image
data to be created in such a manner as mentioned above.

[0108] FIG. 10A and FIG. 10B show a position of an actual object, and FIG.
10B shows a state after elapse of one frame from FIG. 10A. Moreover, FIG.
10C and FIG. 10D individually show frame image data created in the states
of FIG. 10A and FIG. 10B, respectively, and FIG. 10E shows synthetic
image data as a result of synthesizing the frame image data shown in FIG.
10C and FIG. 10D with each other.

[0109] Moreover, FIG. 11A and FIG. 11B show positions of an actual object,
and FIG. 11B shows a state after elapse of one frame from FIG. 11A.
Moreover, FIG. 11C and FIG. 11D individually show frame image data
created in the states of FIG. 11A and FIG. 11B, respectively, and FIG.
11E shows synthetic image data as a result of synthesizing the frame
image data shown in FIG. 11C and FIG. 11D with each other.

[0110] In the example shown in FIG. 10, as shown in FIG. 10A and FIG. 10B,
the object is in a static state during one frame. Therefore, when the
frame image data obtained in the respective frames are synthesized with
each other to create the synthetic image data, then as shown in FIG. 10E,
synthetic image data that that represents substantially the same shape as
that of the actual object can be obtained.

[0111] However, in the example shown in FIG. 11, as shown in FIG. 11A and
FIG. 11B, the object moves during one frame. Therefore, a positional
shift occurs between an image of the object in FIG. 11C and an image of
the object in FIG. 11D. Accordingly, when the frame image data obtained
in the respective frames are merely synthesized with each other to create
the synthetic image data, then as shown in FIG. 11E, comb-like noise
(combing noise) is generated.

[0112] In this connection, in the first embodiment, the synthetic image
data is created with the above-mentioned configuration, whereby the
generation of the comb-like noise is suppressed. A specific description
is made below while referring to FIG. 12 to FIG. 16.

[0113] FIG. 12A, FIG. 12B and FIG. 12C individually show positions of the
actual object. Then, FIG. 12B shows a state after elapse of one frame
from FIG. 12A, FIG. 12C shows a state after elapse of one frame from FIG.
12B. Moreover, FIG. 12D, FIG. 12E and FIG. 12F individually show frame
image data created in the states of FIG. 12A, FIG. 12B and FIG. 12C.

[0114] Then, as shown in FIG. 12, the object does not move during one
frame from the state of FIG. 12A, and turns to the state of FIG. 12B, and
moreover, the object moves during one frame from the state of FIG. 12B,
and turns to the state of FIG. 12C.

[0115] Note that a description is made on the assumption that FIG. 12A and
FIG. 12C show odd number frames, and that FIG. 12B shows an even number
frame.

[0116] Then, the generation of the synthetic image data in a portion
surrounded by broken lines A in FIG. 12 is performed in accordance with
such an aspect as shown in FIG. 13.

[0117] Here, with regard to the pixel data of the frame image in the
portion of the broken lines A of the first frame, pixels in first, third,
thirteenth and fifteenth targets thereof are black, and pixels in fifth,
seventh, ninth and eleventh targets thereof are white.

[0118] Moreover, with regard to the pixel data of the frame image in the
portion of the broken lines A of the second frame, pixels in second,
fourth, twelfth, fourteenth and sixteenth targets thereof are black, and
pixels in sixth, eighth, tenth targets thereof are white.

[0119] Furthermore, with regard to the pixel data of the frame images in
the portion of the broken lines A of the third frame, all of pixels in
first, third, fifth, seventh, ninth, eleventh, thirteenth and fifteenth
targets thereof are black.

[0120] First, the frame image data of the first frame and the third frame
are compared with each other for each of the pixels, and based on
brightness differences therebetween, pixels which move are extracted.
That is, as shown in FIG. 13, pixels which have moved in the portion of
the broken lines A are the pixels of the fifth, seventh, ninth and
eleventh targets.

[0121] Then, at the time of creating the synthetic image data, with regard
to pixels other than the pixels which have moved, the pixel data of the
pixels in the frame image data of the second frame and the pixel data of
the pixel in the frame image data of the third frame are directly applied
as the synthetic image data.

[0122] Moreover, with regard to the pixels which have moved, interpolated
pixel data are obtained from the pixel data of the pixels corresponding
to the pixels which become adjacent to the pixel concerned in the
scanning direction in the event where the synthetic image data is
created, and these are applied as the synthetic image data. That is to
say, for example, with regard to the pixel of the fifth target, an
average of the respective image data of the pixels of the fourth and
sixth targets in the frame image data of the second frame is obtained,
whereby the interpolated image data is obtained, and this is applied as
the pixel data of the pixel of the fifth target in the synthetic image
data. Hence, the pixel of the fifth target becomes gray. Also with regard
to the pixels of the seventh, ninth and eleventh targets, interpolated
pixel data are obtained in a similar way.

[0123] Moreover, the generation of the synthetic image data in a portion
surrounded by broken lines B in FIG. 12 is performed in accordance with
such an aspect as shown in FIG. 14.

[0124] Here, with regard to the pixel data of the frame image in the
portion of the broken lines B of the first frame, the pixels in the
first, third, thirteenth and fifteenth targets are black, and the pixels
in the fifth, seventh, ninth and eleventh targets are white.

[0125] Moreover, with regard to the pixel data of the frame image in the
portion of the broken lines B of the second frame, the pixels in the
second, fourth, twelfth, fourteenth and sixteenth targets are black, and
the pixels in the sixth, eighth, tenth targets are white.

[0126] Furthermore, with regard to the pixel data of the frame image in
the portion of the broken lines B of the third frame, the pixels in the
first, third, thirteenth and fifteenth targets are black, and the pixels
in the fifth, seventh, ninth and eleventh targets are white.

[0127] In a similar way, the frame image data of the first frame and the
third frame are compared with each other for each of the pixels, and
based on brightness differences therebetween, pixels which move are
extracted. With regard to the portion surrounded by the broken lines B,
the pixels which move are not detected, and accordingly, at the time of
creating the synthetic image data, for all of the pixels of the first to
sixteenth targets, the pixel data of the pixels in the frame image data
of the second frame and the pixel data of the pixels in the frame image
data of the third frame are directly applied as the synthetic image data.

[0128] Moreover, the generation of the synthetic image data in a portion
surrounded by broken lines C in FIG. 12 is performed in accordance with
such an aspect as shown in FIG. 15.

[0129] Here, with regard to the pixel data of the frame image in the
portion of the broken lines C of the first frame, all of the pixels in
the first, third, fifth, seventh, ninth, eleventh, thirteenth and
fifteenth targets are black.

[0130] Moreover, with regard to the pixel data of the frame image in the
portion of the broken lines C of the second frame, all of the pixels in
the second, fourth, sixth, eighth, tenth, twelfth, fourteenth and
sixteenth targets are black.

[0131] Furthermore, with regard to the pixel data of the frame image in
the portion of the broken lines C of the third frame, the pixels in the
first, third, thirteenth and fifteenth targets are black, and the pixels
in the fifth, seventh, ninth and eleventh targets are white.

[0132] In a similar way, the frame image data of the first frame and the
third frame are compared with each other for each of the pixels, and
based on brightness differences therebetween, pixels which move are
extracted. That is to say, as shown in FIG. 15, pixels which have moved
in the portion of the broken lines C are the pixels of the fifth,
seventh, ninth and eleventh targets. Then, the generation of the
synthetic image data is performed in such a manner as mentioned above in
FIG. 13.

[0133] Such processing as described above is performed, whereby synthetic
image data as shown in FIG. 16 is created.

[0134] As a result, the comb-like noise as shown in FIG. 11E is not
generated, and it is made possible to achieve reduction of an artifact.

Second Embodiment

[0135] Next, a description is made of a second embodiment of the present
invention. Note that the second embodiment of the present invention is
similar to the first embodiment except that image data synthesis
processing thereof is different from that of the first embodiment, and
accordingly, a description is made of the image data synthesis processing
according to the second embodiment, and a description of other
configurations is omitted.

[0136] While referring to FIG. 17, a description is made of the image data
synthesis processing according to the second embodiment. Note that, in
the second embodiment, the selection of the creation method of the pixels
by the interpolated data method selection unit 18d is performed by the
odd-numbered scan vertical data correlation detection unit 18a, the
even-numbered scan vertical data correlation detection unit 18b and the
frame difference motion detection unit 18c.

[0137] First, in a similar way to the first embodiment, the control unit
18 determines whether or not the subject of the pixel data of the pixel
of interest is the pixel data in the frame image data of the latest frame
(Step S401). When the control unit 18 does not determine that the subject
of the pixel data of the pixel of interest is the pixel data in the frame
image data of the latest frame (Step S401: N), the control unit 18 uses,
as the pixel data of the pixel of interest, the pixel data in the frame
image data of the second latest frame (Step S402).

[0138] Meanwhile, when the control unit 18 determines that the subject of
the pixel data of the pixel of interest is the pixel data in the frame
image data of the latest frame (Step S401: Y), then by functions of the
odd-numbered scan vertical data correlation detection unit 18a and the
even-numbered scan vertical data correlation detection unit 18b, the
control unit 18 extracts the pixel data (vertical pixel data) of the
pixels, which correspond to the pixels adjacent to the pixel of interest
in the vertical direction (scanning direction), from the frame image data
of the second latest frame, and detects a brightness difference between
the extracted pixels in such a manner as mentioned above (Step S403).

[0139] Then, the control unit 18 determines whether or not a correlation
between the vertical pixel data is strong as a result of detecting the
brightness difference (Step S404).

[0140] When the control unit 18 determines that the correlation between
the vertical pixel data is strong (S404: Y), then by the functions of the
interpolated data method selection unit 18d and the interpolated data
selection unit 18e, the control unit 18 writes interpolated data, which
is created by obtaining an average of the vertical pixel data, as the
pixel data of the pixel of interest into the work area of the memory unit
15 (Step S405). Meanwhile, when the control unit 18 does not determine
that the correlation between the vertical pixel data is strong (Step
S404: N), the control unit 18 executes processing of Step S406 and after.
Contents of the processing of Step S406 and after are similar to contents
of the processing of Step S303 to Step S308 of FIG. 7, and accordingly, a
description thereof is omitted.

[0141] Next, while referring to FIG. 18 to FIG. 21, a specific description
is made of a creation process of the synthetic image data in the second
embodiment. Note that the obtaining conditions of the frame image data
and the positions of the pixels in the synthetic image data, which are
used in the description, are assumed to be similar to those in the
description of FIG. 12.

[0142] In the second embodiment, the generation of the synthetic image
data in the portion surrounded by the broken lines A in FIG. 12 is
performed in accordance with an aspect shown in FIG. 18.

[0143] First, the vertical pixel data as pixel data of the pixels, which
correspond to the pixels adjacent to the pixel of interest in the
vertical direction, are extracted. That is to say, for example, if the
pixel of interest is the pixel of the third target, then the pixel data
to be extracted as the vertical pixel data are the pixel data of the
pixels of the second and fourth targets in the frame image data of the
second frame. Moreover, if the pixel of interest is the pixel of the
fifth target, then the pixel data to be extracted as the vertical pixel
data are the pixel data of the pixels of the fourth and sixth targets in
the frame image data of the second frame.

[0144] Then, the brightness difference between the vertical pixel data is
detected to determine strength of the correlation. In the case where the
correlation is strong, then the interpolated pixel data is obtained from
the vertical pixel data, and this is applied as the pixel data of the
pixel of interest to the synthetic image data. That is to say, for
example, with regard to the pixel of the third target, since a
correlation between the respective pixel data of the pixels of the second
and fourth targets is strong, an average of these pixel data is obtained,
whereby the interpolated pixel data is obtained, and this is applied as
the pixel data of the pixel of the third target in the synthetic image
data.

[0145] Meanwhile, in the case where the correlation between the vertical
pixel data is not strong, then it is further determined whether or not
the pixel of interest has moved. Note that, since a method of determining
such a motion is similar to that of the first embodiment, a detailed
description thereof is omitted. For example, with regard to the pixel of
the fifth target, a correlation between the respective pixel data of the
pixels of the fourth and sixth targets in the frame image data of the
second frame is not strong (is low), and accordingly, the motion
determination is performed for the pixel of interest. Then, since the
pixel of interest has moved, an average of the vertical image data is
obtained to obtain interpolated pixel data, and this is applied as pixel
data of the pixel of the fifth target in the synthetic image data. Hence,
the pixel of the fifth target becomes gray.

[0146] Moreover, with regard to the creation of the synthetic image data
in the portion surrounded by the broken lines B in FIG. 12, as shown in
FIG. 19, the creation of the synthetic image data is performed by a
similar process.

[0147] Here, with regard to each of pixels denoted by "Data A" and "Data
B" in FIG. 19, pixel data is obtained as shown in FIG. 20A. That is to
say, with regard to the pixel of the fifth target, which is the pixel of
interest and is denoted by "Data A", a correlation between the respective
pixel data of the pixels of the fourth and sixth targets in the frame
image data of the second frame is low, and accordingly, the motion
determination is performed for the pixel of interest. Then, since the
pixel of interest has not moved, pixel data of a pixel (pixel denoted by
"1" in FIG. 20A) in the frame image data of the third frame is directly
applied as the synthetic image data. In FIG. 19, also with regard to the
pixel of the eleventh target, which is the pixel of interest and is
denoted by "Data B", pixel data is obtained in a similar way.

[0148] Note that, with regard to the pixel data of each of the pixels
denoted by "Data A" and "Data B", a similar effect is obtained even if
such aspects as shown in FIG. 20B and FIG. 20C are used as well as the
aspect shown in FIG. 20A. That is to say, in the aspect shown in FIG.
20B, pixel data of the pixel (pixel denoted by "0" in FIG. 20B) in the
frame image data of the first frame is directly applied as the synthetic
image data. Moreover, in the aspect shown in FIG. 20C, one obtained by
averaging the pixel data of the pixel (pixel denoted by "0" in FIG. 20C)
in the frame image data of the first frame and the pixel data of the
pixel (pixel denoted by "1" in FIG. 20C) in the frame image data of the
third frame is applied as the synthetic image data.

[0149] Moreover, with regard to the creation of the synthetic image data
in the portion surrounded by the broken lines C in FIG. 12, as shown in
FIG. 21, the creation of the synthetic image data is performed by a
similar process to that mentioned above.

[0150] Note that, with regard to the pixel of the first target as an upper
end portion of the frame image, the motion detection by the brightness
difference, which is as shown in the first embodiment, is performed,
whereby the creation of the pixel data is performed; however, the pixel
data of the pixel of the second target in the frame image data of the
second frame may be applied. Moreover, in the case where the latest frame
is an even number frame, with regard to the pixel of the sixteenth target
as a lower end portion of the frame image, pixel data of the pixel of the
fifteenth target in an odd number frame as the second latest frame may be
applied.

[0151] As described above, also by the second embodiment, a similar effect
to that of the first embodiment is obtained.

Third Embodiment

[0152] Next, a description is made of a third embodiment of the present
invention. Note that the third embodiment of the present invention is
similar to the first and second embodiments except that image data
synthesis processing thereof is different from those of the first and
second embodiments, and accordingly, a description is made of the image
data synthesis processing according to the third embodiment, and a
description of other configurations is omitted.

[0153] While referring to FIG. 22, a description is made of the image data
synthesis processing according to the third embodiment. Here, a
description is made of Step S405a and Step S409a, which are different
from equivalent steps in the image data synthesis processing according to
the second embodiment, and since pieces of processing in other steps are
similar to equivalent pieces in the image data synthesis processing
according to the second embodiment, a description thereof is omitted.

[0154] In Step S405a, the control unit 18 writes upper pixel data between
the vertical pixel data as the interpolated data into the work area of
the memory unit 15 (Step S405a). That is to say, when illustration is
made with reference to FIG. 18, then with regard to the pixel of
interest, which is the pixel of the third target, the pixel data of the
pixel of the second target between the respective pixel data (vertical
pixel data) of the pixels of the second and fourth targets in the frame
image data of the second frame is directly applied as the pixel data of
the pixel of the third target.

[0155] Moreover, in a similar way also in Step S409a, the control unit 18
writes upper pixel data between the vertical pixel data as the
interpolated data into the work area of the memory unit 15 (Step S409a).
That is to say, when illustration is made with reference to FIG. 18, then
with regard to the pixel of interest, which is the pixel of the fifth
target, the pixel data of the pixel of the fourth target between the
respective pixel data (vertical pixel data) of the pixels of the fourth
and sixth targets in the frame image data of the second frame is directly
applied as the pixel data of the pixel of the fifth target. Hence, in the
third embodiment, the pixel of the fifth target becomes black, and
meanwhile, the pixel of the eleventh target becomes white as a result of
performing similar processing.

[0156] Note that, in place of Step S409a, Step S409 of the image data
synthesis processing shown in FIG. 17 may be executed.

[0157] The processing as described above is performed, whereby such
synthetic image data as shown in FIG. 23 is created.

[0158] As described above, in accordance with the third embodiment, the
comb-like noise is not generated, and it is made possible to achieve the
reduction of the artifact. Moreover, more than in the case of obtaining
the interpolated data by averaging the vertical pixel data, it is made
possible to reduce a processing load, or alternatively, to simplify the
circuit configuration in the case of realizing the processing by
hardware, and a reduction of cost can be achieved.

Fourth Embodiment

[0159] Next, a description is made of a fourth embodiment of the present
invention. Note that the fourth embodiment of the present invention is
similar to the first and second embodiments except that image data
synthesis processing thereof is different from those of the first and
second embodiments, and accordingly, a description is made of the image
data synthesis processing according to the fourth embodiment, and a
description of other configurations is omitted.

[0160] While referring to FIG. 24, a description is made of the image data
synthesis processing according to the fourth embodiment. Here, a
description is made of Step S405b and Step S409b, which are different
from equivalent steps in the image data synthesis processing according to
the second embodiment, and since pieces of processing in other steps are
similar to equivalent pieces in the image data synthesis processing
according to the second embodiment, a description thereof is omitted.

[0161] In Step S405b, the control unit 18 writes lower pixel data between
the vertical pixel data as the interpolated data into the work area of
the memory unit 15 (Step S405b). That is to say, when illustration is
made with reference to FIG. 18, then with regard to the pixel of
interest, which is the pixel of the third target, the pixel data of the
pixel of the fourth target between the respective pixel data (vertical
pixel data) of the pixels of the second and fourth targets in the frame
image data of the second frame is directly applied as the pixel data of
the pixel of the third target.

[0162] Moreover, in a similar way also in Step S409b, the control unit 18
writes lower pixel data between the vertical pixel data as the
interpolated data into the work area of the memory unit 15 (Step S409b).
That is to say, when illustration is made with reference to FIG. 18, then
with regard to the pixel of interest, which is the pixel of the fifth
target, the pixel data of the pixel of the sixth target between the
respective pixel data (vertical pixel data) of the pixels of the fourth
and sixth targets in the frame image data of the second frame is directly
applied as the pixel data of the pixel of the fifth target. Hence, in the
fourth embodiment, the pixel of the fifth target becomes white, and
meanwhile, the pixel of the eleventh target becomes black as a result of
performing similar processing.

[0163] Note that, in place of Step S409b, Step S409 of the image data
synthesis processing shown in FIG. 17 may be executed.

[0164] The processing as described above is performed, whereby such
synthetic image data as shown in FIG. 25 is created. As described above,
in accordance with the fourth embodiment, a similar effect to that of the
third embodiment can be exerted.

[0165] As described above, in accordance with the first to fourth
embodiments of the present invention, the ultrasound probe 2 includes the
n pieces of transducers 2a while arranging the transducers 2a in
parallel, the transducers 2a outputting the transmitted ultrasound waves
toward the test body by the drive signal, and in addition, outputting the
received signals by receiving the reflected ultrasound waves from the
test body. Then, the transmitter unit 12 supplies the drive signal to the
selected transducers 2a among the n pieces. Then, the receiver unit 13
receives the received signals to be outputted from the selected
transducers 2a. Then, the control unit 18 sequentially selects the
transducers 2a, which are to be supplied with the drive signal, while
shifting the transducers 2a by a predetermined number in the array
direction every time when each of the transmitted ultrasound waves is
outputted. Then, based on the received signals sequentially received by
the receiver unit 13, the image creation unit 14 creates the image data
of the inside of the test body for each of the frames. Then, while making
switch for each of the frames, the control unit 18 executes the selection
of the m pieces of the transducers 2a arranged consecutively and the
selection of the m+1 pieces of the transducers 2a arranged consecutively.
Then, every time when the image data of each of the frames is created,
the control unit 18 at least creates the synthetic image data obtained by
synthesizing the image data of the two consecutive frames with each
other. As a result, the interval between the targets, which depends on
the interval between the transducers, can be reduced, and accordingly,
the resolution can be enhanced. In addition, the scanning is performed
while changing the number of driven transducers, which perform the
transmission/reception, to the odd number/even number for each of the
frames, and accordingly, the lowering of the frame rate can be
suppressed.

[0166] Moreover, in accordance with the first to fourth embodiments of the
present invention, the memory unit 15 at least stores the image data of
the range from the latest frame between the two consecutive frames to the
third latest frame. Then, the control unit 18 creates the pixel data of
the pixel in the synthetic image data, which corresponds to a changed
portion of the pixel between the image data of the latest frame and the
image data of the third latest frame, based on the pixel data in the
image data of the second latest frame, which corresponds to the pixels
adjacent to the pixel concerned. As a result, it is made possible to
suppress the generation of the comb-like noise, and accordingly, the
artifact can be reduced.

[0167] Moreover, in accordance with the first and second embodiments, the
control unit 18 sets the pixel data of the pixel in the synthetic image
data, which corresponds to the changed portion of the pixel, to the one
obtained by the interpolation from the pixel data in the image data of
the second latest frame, which individually correspond to the pixels
adjacent to both sides of the pixel concerned in the azimuth direction.
As a result, the generation of the comb-like noise is suppressed, and in
addition, image data more approximate to such a measurement subject can
be obtained, and accordingly, enhancement of image quality can be
achieved in addition to the reduction of the artifact.

[0168] Moreover, in accordance with the first to fourth embodiments of the
present invention, the control unit 18 sets the pixel data of the pixel
in the synthetic image data, which corresponds to the changed portion of
the pixel, to the same one as the pixel data in the image data of the
second latest frame, which corresponds to the pixel adjacent to either
side of the pixel concerned in the azimuth direction. As a result, it is
made possible to suppress the generation of the comb-like noise, and
accordingly, the artifact can be reduced. Furthermore, a special
calculation and the like for obtaining the pixel data are not necessary,
and the processing is simplified, or alternatively, can be realized by a
simple circuit configuration, whereby the reduction of the cost is
achieved. Moreover, the image can be displayed more clearly and
distinctively, and accordingly, the enhancement of the image quality can
also be achieved.

[0169] Moreover, in accordance with the first embodiment of the present
invention, the control unit 18 sets the pixel data of the pixel in the
synthetic image data, which corresponds to the portion where there is no
change in the pixel between the image data of the latest frame and the
pixel data of the third latest frame, to the pixel data of the pixel in
the image data of the latest frame, which corresponds to the pixel
concerned. As a result, a special calculation and the like for obtaining
the pixel data are not necessary, and the processing is simplified, or
alternatively, can be realized by a simple circuit configuration, whereby
the reduction of the cost is achieved.

[0170] Moreover, in accordance with the second to fourth embodiments of
the present invention, the control unit 18 determines whether or not the
two pixels adjacent to each other in the azimuth direction in the image
data of the second latest frame, which serve as the determination subject
pixels, satisfy a predetermined correlation condition. Then, when the
correlation condition is satisfied as a result of the determination, the
control unit 18 sets the pixel data of the pixel arranged between the two
pixels in the synthetic image data, which correspond to the determination
subject pixels, to the one created based on the pixel data related to the
determination subject pixels concerned. As a result, the creation aspect
of the pixel data is decided by determining the correlation, and
accordingly, the simplification of the processing can be achieved, or
alternatively, it is made possible to realize the processing by a simple
circuit configuration, whereby the reduction of the cost is achieved.

[0171] Moreover, in accordance with the second to fourth embodiments of
the present invention, the control unit 18 determines, as a correlation
condition, whether or not the brightness difference between the
determination subject pixels is a predetermined threshold value or less,
and accordingly, the determination of the correlation condition can be
performed with ease.

[0172] Note that the description in the embodiments of the present
invention merely illustrates examples of the ultrasound diagnostic device
according to the present invention, and the ultrasound diagnostic device
according to the present invention is not limited to this. Detailed
configurations and detailed operations of the respective functional units
which compose the ultrasound diagnostic device are also changeable as
appropriate.

[0173] Moreover, in this embodiment, the odd number scanning unit 13b and
the even number scanning unit 13c are formed in the one receiver unit 13;
however, such a configuration may be adopted, in which a plurality of the
receiver units are provided, and the odd number scanning unit 13b and the
even number scanning unit 13c are individually provided in the receiver
units separate from each other.

[0174] Moreover, in this embodiment, the odd-numbered scan B-mode image
creation unit 14a and the even-numbered scan B-mode image creation unit
14 are formed in the one image creation unit 14; however, such a
configuration may be adopted, in which a plurality of the image creation
units 14 are provided, and the odd-numbered scan B-mode image creation
unit 14a and the even-numbered scan B-mode image creation unit 14b are
individually provided in the image creation units separate from each
other.

[0175] Moreover, in this embodiment, the odd-numbered scan B-mode image
data memory unit 15a and the even-numbered scan B-mode image data memory
unit 15b are formed in the one memory unit 15; however, such a
configuration may be adopted, in which a plurality of the memory units
are provided, and the odd-numbered scan B-mode image data memory unit 15a
and the even-numbered scan B-mode image data memory unit 15b are
individually provided in the memory units separate from each other.

[0176] Moreover, in the first embodiment, in the case where the pixel of
interest moves, then the average of the pixel data of the pixels
corresponding to the pixels adjacent thereto in the vertical direction is
obtained to create the interpolated data; however, as in the third or
fourth embodiment, the upper data or the lower data may be used as the
interpolated data. Moreover, these may be used in combination with each
other.

[0177] Moreover, in this embodiment, the determination of the brightness
difference is performed for each of the pixels, and the motion is
detected; however, for example, such a configuration may be adopted, in
which a plurality of pixels composed of x×y pieces (each of x and y
is an integer of one or more) are defined as a unit of block, brightness
averages are obtained for each of the blocks, and values of the averages
are compared with one another to determine the brightness difference, and
the motion detection is performed. In such a way, a reduction of an
arithmetic operation amount can be achieved, and moreover, in the case
where noise is superimposed, this can be absorbed. Accordingly, even in
the case where the noise is generated, it is made possible to reduce an
influence thereof.

[0178] Moreover, in the second to fourth embodiments, the correlation
between the pixels is determined from the brightness difference between
the vertical pixel data; however, such a configuration may be adopted, in
which a plurality of pixels composed of x×y pieces (each of x and y
is an integer of one or more) are defined as a unit of block, brightness
averages are obtained for each of the blocks, and values of these
averages are compared with each other between the upper and lower blocks
to determine the brightness difference, and the determination is
performed between the upper and lower blocks. Then, from a result of such
a correlation determination, the interpolated pixel data may be obtained
based on the respective average values of the upper and lower blocks for
the pixel of the target arranged between these blocks or for the
plurality of pixels turned to the unit of block. In such a way, the
reduction of the arithmetic operation amount can be achieved, and
moreover, in the case where noise is superimposed, this can be absorbed.
Accordingly, even in the case where the noise is generated, it is made
possible to reduce the influence thereof.

[0179] Moreover, in this embodiment, the example is disclosed, where a
hard disk, a semiconductor nonvolatile memory or the like is used as a
medium capable of reading a program according to the present invention by
a computer; however, the present invention is not limited to this
example. As another computer-readable medium, a portable recording medium
such as a CD-ROM is applicable. Moreover, a carrier wave is also applied
as a medium that provides data of the program according to the present
invention through a communication line.

INDUSTRIAL APPLICABILITY

[0180] The present invention is applicable in the field (particularly, the
medical field) where the diagnosis is performed by the ultrasound image.